Using salmonid fish as research subjects, we will study various aspects of decompression and associated problems. Experiments with inert gasses having widely differing solubilities will be used to improve our definition of the supersaturation conditions leading to bubble formation. Techniques used include a tensiometer, measurement of gas uptake and elimination from the fish's environment, implantation of a Doppler blood flowmeter to detect bubbles, and bioassays of various diving conditions. Our previous work also showed that blood clotting accelerated under stress, including decompression, and then was followed by consumptive coagulation. Work this year will be to define the role of thrombocytes and adrenalin in decompression-induced clotting. Tissue damage to heart muscle and other muscle tissue, which we identified from elevated plasma levels of the enzyme, creatine phosphokinase, will be described with light and electron microscopy. These findings will contribute to basic theory of diving decompression.